Single boom derrick units



16 Sheets-Sheet 1 R. O. BALOGH ETAL SINGLE BOOM DERRICK UNITS INVENTORS ATTORNEY Oct. 27, 1964 Filed Sept. 4, 1962 ROY O. BALOGH ROBERT G. BAKULA mt rn D SIL m9 om. @E

Oct. 27, 1964 R. o. BALOGH ETAL 3,154,199

SINGLE BOOM DERRICK UNITS Filed Sept. 4, 1962 16 Sheets-Sheet 2 INVENTOR. ROY O. BALOGH ROBERT O. BAKULA ATTORNEY Oct. 27, 1964 R. o. BALOGH ETAL 3,154,199

SINGLE Boom DERRICK UNITS Filed sept. 4, 1962 16 sheets-sheet s ROY O. BALOGH ROBERT G. BAKULA www ATTORNEY Oct. 27, 1964 R. o. BALOGH ETAL 3,154,199

SINGLE: Boom DERRICK UNITS Filed Sept. 4, 1962 16 Sheets-Sheet 4 FIG. lO

INVENTOR. ROY O. BALOGH ROBERT G. BAKULA ATTORNEY Oct. 27, 1964 R. o. BALOGH ETAL 3,154,199

SINGLE BOOMYDERRICK UNITS Filed Sept. 4, 1962 16 Sheets-Sheet 5 ATTORNEY Oct.`27, 1964 R. o. BALoGH ETAL SINGLE BooM DERRIcx UNITS 16 Sheets-Sheet 6 Filed sept. 4, 1962 |92 FIG. I4

FIG. l5

INVE'NT OR. ROY O. BALOGH BY ROBERT G. BAKULA ATTORN EY Oct. 27, 1964 R. o. BALOGH ETAL 3,154,199

SINGLE Boom DERRIcx UNITS Filed sept. 4, 1962 1e sheets-sheet 7 ATTORNEY Oct. 27, 1964 R. o. BALoGH ETAL 3,154,199'

SINGLE Boom DERRICK UNITS Filed Sept. 4, 1962 16 Sheets-Sheet 8 lllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll 1311. nlllalllf INVENTOR. ROY O. BALOGH ROBERT G. BAKULA ATTORNEY Oct. 27, 1964 R. o. BALoGH ETAL 3,154,199

SINGLE Boom DERRICK YUNITS 16 Sheets-Sheet 9 Filed Sept. 4, 1962 www ATTO RNEY Oct. 27, 1964 R. o. BALOGH ETAL 3,154,199

SINGLE Boom DERRICK UNITS Filed sept. v4, 1962 16 Sheets-Sheet 10 INVENTOR. ROY O. BALOGH BY ROBERT G. BAKULA @mm O E 8m N @om mm Rm www, FJ mmm M -l I Il! Il! l h I HHN. ||l|| luk O I -I dh- -huhhnnnhhui fhunvh :HH r omm .lN m\ 5k vom\ m ATTO RNEY Oct. 27, 1964 R. o. BALOGH ETAL 3,154,199

SINGLE Boom DERRICK UNITS 16 Sheecs-SheefI 11 Filed Sept. 4, 1962 INVENTOR. ROY O. BALOGH ROBERT G. BAKULA JmoN ATTORNEY Oct. 27, 1964 R. o. BALoGH ETAL 3,154,199

SINGLE BooM DERRICK UNITS Filed Sept. 4, 1962 16 Sheets-Sheet 12 Ill FIG. 29

3l FIG. 30

INVENTOR. ROY O. BALOGH ROBERT G. BAKULA BY ATTOR NEY Oct. 27, 1964 R. o. BALoGH ETAL 3,154,199

SINGLE Boom DERRICK UNITS Filed Sept. 4, 1962 16 Sheets-Sheet 13 32 o f 372 c s Il.. 370 355 356 aeg-f l 353 I I 354 366` I 3 376 I o 367- 357 1 I 373 |I Il. r 272 274 l l 364 Il I 364 l wir, h. 36 363 Y Y l L FIG. 3l 32 372 7: 372 37| 372 372 355 WWII N `61 1l 369 366 y 276 h 26o 36o 353 l I l 36o V l FIG. 32 i INVENTOR. ROY o. BALOGH ROBERT G. BAKULA 264 ATTORNEY R. o. BALOGH ETAL 3.154,199

SINGLE Boom DERRICK UNITS 16 Sheets-Sheet 14 Oct. 27, 1964 Filed Sept. 4, 1962 Se Q w N v Q TL, L T- L @mv om L mm 0.... 9v Q @vm o3 Sm \\a mv 3m mm HH z: I ,l A s Il l. x f om w f m\ om@ m`.m\\ 5m mmm man om mov um mmm N emv @om m 0mm 2m 3m SN mm mmm INVENTOR. ROY O. BALOGH ROBERT G. BAKULA BY ATTORNEY Oct. 27, 1964 R. o. BALOGH ETAL 3,154,199

SINGLE BOOM DERRICK UNITS Filed Sept. 4, 1962 16 Sheets-Sheet 15 FIG. 36 402 i INVENTOR. ROY O. BALOGH ROBERT G. BAKULA www ATTORNEY Oct. 27, 1964 R. O. BALOGH ETAL.

SINGLE BOOM DERRICK UNITS 16 Sheets-Sheet 16 Filed Sept. 4, 1962 INVENTOR. ROY O. BALOGH ROBERT G. BAKULA www ATTORNEY United States Patent O 3,154,199 SHQGLE EGSM BEREICH UNITS Iloy 0. Balogh, La Due, and Robert G. Battute, Hanley Hills, Mo., assignors to ll'IcCahe-Powers Body Conipany, St. Louis, Mo., a corporation of Missouri Filed Sept. 4, 1%2, Ser. No. 221,225 14 lajms. (Cl. 212-35) This invention relates in general to certain new and useful improvements in rotatable derricks which are adapted for use on trucks or similar mobile platforms.

Many industrial organizations, such as public utilities, often use service maintenance trucks which are provided with some type of rotatable derrick. These derricks are usually provided with accessory devices for digging holes, setting poles into the ground, and for lifting various loads. The derrick usually is mounted on the truck body adjacent to the cab of the truck, and extends rearwardly over the bed of lthe truck in a substantially horizontal position or so-called transport position. When at the work site, the derrick is usually moved to its work position where it can assume a plurality of various positions with respect to the truck. Such derricks are usually capable of pivoting along a plane which is parallel to the longitudinal axis of the truck and it is also capable of rotating through an arc in a horizontal plane.

However, when the derrick is rotated to a position with the outer end thereof extending over one of the sides of the truck, it can only be lowered to a point where it abuts the upper margin of the truck body. It is, however, impossible to lower the derrick to a position Where it is capable of operating some accessory device close to the ground. Oftentimes, it is desirable to attach a hole digger to the end of the derrick in order to drill a post hole. In order to function properly, the post hole digger must operate in a very close proximity to the ground level and, therefore, it is desirable to swing the derrick to a position where it is slightly above the ground level. Moreover, the derricks are often iitted with baskets mounted on the upper end thereof for work on telephone poles and highelectrical wires. It is, of course, desirable to lower the basket to a position for convenient loading and unloading of the personnel who are carried by the basket. Heretofore, there has been no derrick which is capable of being lowered to a point where the free end is in close proximity to the level of the ground.

It is, therefore, the primary object of the present invention to provide a portable derrick which can be quickly and eliciently swung from an inoperative transport position to various work positions.

It is another object of the present invention .to provide a portable derrick of the type stated which may be mounted on a mobile platform such as a truclr and which is capable of vertical and horizontal swinging movement.

Itis an additional object of the present invention to provide a portable derrick of the type stated which is adapted for accommodating accessory devices such as hole diggers, work platforms, and the like.

It is also an object of the present invention to provide a portable derrick of the type stated with a unique hydraulic operating system whereby a great degree of extension can be achieved without causing critical deection or distortion.

It is an additional object of the present invention to provide a portable derrick of the type stated which is constructed in a single unit and equipped with outriggers, so that the single unit derrick can be suitably mounted on any truck name.

With the above and other objects in View, our invention resides in the novel features of form, construction, arrangement, and combination of parts presently described and pointed out in the claims.

In the accompanying drawings (sixteen sheets)- 3,l54,l99 Fatented Oct. 27, 1964 ICC FIG. 1 is a side elevational view of a rotatable derrick constructed in accordance with and embodying the present invention, and being suitably mounted on a truck body;

FIG. 2 is a top plan view of the rotatable derrick of FIG. 1;

FIG. 3 is a left end elevational view of the rotatable derriclr;

FIG. 4 is a fragmentary sectional View taken along line 4-4 of FIG. 1;

FIGS. 5 and 6 are fragmentary sectional views taken along lines S-S and 6 6, respectively, of FIG. 4;

FIG. 7 is a sectional view taken along line 7--7 of FIG. 5;

FIGS. 8 and 9 are fragmentary sectional views taken along lines S-S and 9--9, respectively, of FIG. 4;

FIG. 10 is `a fragmentary sectional View taken along line 16--19 of FIG. 2;

FIG. 11 is a fragmentary sectional view taken along line 11-11 of FIG. 10;

FIG. 12 is a fragmentary sectional view taken along line I2-12 of FIG. 11;

FIGS. 13 and 14 are sectional views taken along lines 1.3-13 and 14-14, respectively, of FIG. 1;

FIG. 15 is a fragmentary sectional view along line 15-15 of FIG. 2;

FIG. 16 is a fragmentary sectional View taken along line 16-16 of FIG. 15;

FIG. 17 is a fragmentary sectional view taken along line 17-17 of FIG. 16;

FIGS. 18 and 19 yare sectional views taken along lines 18-18 Iand 19-19, respectively, of FIG. 1;

FIG. 2U is a fragmentary sectional View .taken along line Ztl-26 of FIG. 19;

FIGS. 21 and 22 are fragmentary sectional views taken along lines 21-21 and 22-22 of FIG. 20;

FIG. 23 is a fragmentary sectional View taken along line 23-23 of FIG. 2;

FIG. 24 is a schematic view of the control system and hydraulic circuitry forming part of the single boom derrick unit A;

FIG. 25 is a side elevational View of the modied form of single boom derrick unit constructed in accordance with and embodying the present invention;

FIG. 26 is a top plan view of the derrick unit of FIG. 25;

FIG. 27 is a fragmentary sectional View taken along line 27-27 of FIG. 26;

FIG. 28 is a sectional View taken along line 28-28 of FIG. 25;

FIG. 29 is a fragmentary side elevational view of another modiied form of single boom derrick unit constructed in accordance with and embodying the present invention; 29FIG. 30 is a top plan View of the derrick unit of FIG.

FIG. 31 is a fragmentary sectional view taken along line 31-31 of FIG. 30;

FIG. 32 is a fragmentary sectional view taken along line 32-32 of FIG. 31;

FIG. 33 is a fragmentary side elevational view of a further modifed form of single boom derrick unit constructed in accordance with and embodying the present invention;

FIG. 34 is a vertical sectional view taken along line 34 of FIG. 33

FIG. 35 is a top plan view, partly broken away, of the derrick unit of FIG. 33;

FIG. 36 is a sectional View taken along line 36-36 of FIG. 33;

FIG. 37 is a sectional view of a portion of the control system of the derrick unit of FIG. 33; and

FIG. 38 is a schematic view of the control system and 3 hydraulic circuitry forming part of the derrick unit of FIG. 33.

Referring now in more detail and by reference characters tothe drawings, which illustrate practical embodiments of the present invention, A designates a single Vhoorn derrick unit which is suitably mounted on a conventional truck T, the latter being shown in dotted lines in FIG. 1. The truck Tis generally provided with a pair of lengthwise extending frame members 1 and welded to the exterior vertical walls thereof are support channels 2 and welded to the upper faces thereof is a derrick support frame 3, the latter including a pair of spaced transversely extending cross-bars 4, 5, and welded to the transverse ends thereof are four uprights 6. Welded to the upper ends of each of the two forward uprights 6 and extending transversely thereacross is an upper crossbar 7 and welded to the upper ends of each of the two rearward uprights 6 and extending transversely thereacross is an upper cross-bar 8. Interconnecting each of the Across-bars 7, 8, at their transverse margins is a pair of lengthwise extending support members 9, 10, which are, in turn, supported by gusset plates 11, the latter being welded to the underside of the support members 9, 10, and to the uprights 6. The pair of rearward uprights 6 can further be supported by a pair of rearwardly and downwardly extending braces 12 which are bolted or otherwisesecured at their lower ends to the frame members 1 forming part of the truck T. The cross-bars 4, 5, 7, and 8, andthe uprights 6 are preferably formed from any standard H-shaped rolled steel. As shown in FIGS. 1 and 3, the support frame 3 can Vbe suitably enclosed within a truck body 13 forming'part of the truck T.

Welded to and extending transversely between each of the forward uprights 6, somewhat centrally of their upper and lower ends, is a U-shaped intermediate crossbar 14 and weldedto the cross-bar 14 and each of the forward uprights 6 is a pair of outwardly and downwardly diverging outriggers 15, 16, both of which are substantially'identical and, therefore, only the Outrigger 15 will be illustrated and described in detail herein.

The outrigger 15 comprises a movable hydraulic cylinder 17 which is internally bored to accommodate a stationary tubular piston rod 18 and welded or otherwise rigidly secured to the lower end of the piston rod V18 is a cylindrical plug 19 having an axial fluid duct 29. The plug 19 is turned down at its lower end to form a diametrally reduced portion 21 and an annular shoulder 22. Mounted on the diametrally reduced portion 21 is a cylindrical piston 23 which is interposed between a pair of retaining plates 24, 25, the former of which abuts the annular shoulder 22 and isretained in a locked position by means of a nut 26. The retaining plates 24, 25, are annularly grooved to accommodate annular neoprene rubberl sealing rings 27, 28, which form a tight wiping seal against the wall of the cylinder 17. Welded to the lower end of the hydraulic cylinder 17 is a backing plate 29 which is spaced from the retaining plate 25 forming a fluid chamber 30. Disposed within and extending axially through the Ytubular piston rod 18 is a fluid supply line 31 which is secured at its lower end to the plug 19 and communicates with the chamber 30 through the fluid duct 20. The supply line 31 is spaced froml the inner annular wall of the piston rod 18 forming an annular uid channel 32. The upper end of the tubular piston rod 18 is welded to the underside of a valve block 33 which is integrally provided with an upstanding reduced head 34, the head 34 being tted within the bore of a retaining block 35 and removably secured thereto by means of a removable pin 36. The retaining block 35 is bolted to a U-shaped link 37 which extends along a portion of the exterior surface of, and is welded to, Van Outrigger housing 38 which is, in turn, welded to one of the forward uprights 6 and the cross-bar 14.

Rigidly Vsecured to the upper end of the movable hydraulic cylinder 17 is a cylinder head 39 which is annularly grooved to accommodate a pressure seal 40 and a wiping seal 41, both of which engage the exterior surface of the stationary piston rod 18 as the cylinder 17 moves therelong. The cylinder head 39 is grooved to accommodate compression springs 42 for urging each of the seals 4u, 41, into engagement with the exterior annular surface of the piston rod 18, thereby forming a wiping seal contact. The cylinderhead 39 is integrally formed with a depending annular bumper ange 43 which serves as a limiting means for the extension of the hydraulic cylinder 17 when the bumper ange 43 abuts the upwardly presented surface of the retaining plate 24.

When the outriggers 15, 16, are in an extended position, a rather severe strain would be imposed upon the hydraulic cylinder 17, and cause a serious lateral deflection or buckling. ln order to prevent this rather severe stress upon the hydraulic cylinder 17, an outer support sleeve 44 is concentrically spaced from and secured to the hydraulic cylinder 17 by means of a pair of spacer rings 45, 4S'. By reference to FIG. 4, it can be seen that the piston rod 18 is also concentrically spaced from the internal wall of the cylinder 17, thereby forming an annular iuid chamber 46 which communicates with the fluid channel 32 through apertures o formed in the lower end of the piston rod 18. The support sleeve 44 is axially disposed within the Outrigger housing'38 and is sized forY slidably engaging the internal wall of the housing 3S when the cylinder 17 is extended. The backing plate 29 is integrally formed with a depending boss 47 and pivotally secured thereto by means of a pin 48 is an Outrigger base 49 having an upstanding clevis Si? and a flat undersurface 51 which is adapted to contact the ground when the Outrigger 15 is in the extended position, that is the position as shown in the dotted lines of FIG. 4. The Outrigger housing 38 is integrally formed with a depending tongue'SZ having a lower arcuate edge 53 and when the hydraulic cylinder-17 is in die retracted position, the upper surface of the Outrigger base 49 is adapted to contact the arcuate edge 53 and will pivot to the position as shown in the solid lines of FIG. 4. By means of this construction, it can be seen that when fluid is pumped through the fluid supply line 31 and into the chamber 30, the fluid under pressure will bear against the backing plate 29 which will cause the movable hydraulic cylinder 17 to extend with respect to the stationary piston rod 18.` As this occurs, the weight of the outrigger base 49 will cause the same to pivot to the position as shown in the dotted lines of FIG. 4. When it is desired to retract the Outrigger 15 to the position as shown in the solid lines of FIG. 4, uid is pumped through'the annular iiuid channel 32 and out through the set of apertures o and into'the annular fluid chamber 46. This uid under pressure will bear against the undersurface of the cylinder head 39, causing the cylinder 17 to retract Within the Outrigger housing 3S.

In order to prevent the collapsing of the outriggers 15, 16, in the event that any of the hydraulic uid lines should break, the outriggers 15, 16, are provided with a iluid safety lock system which is mounted within the valve block 33 `and can Abest be seen in FlGS. 5-7. Mounted within the valve block 33 is a pair of uid couplings 55, 56, and formed in the valve block 33 is a pair of radial passageways 57, 53, each of which is plugged at both ends by fluid plugs 59, 59', and 60, 60'. Disposed within the radial passageway 57 is a ball check 61 which is normally biased into engagement with a valve seat 62 formed Within the radial passageway 57, by means of a compression spring 63 which bears against a pin 64, the latter, in turn, bearing against the ball check 61, all as best seen in FIG. 5. Also operatively disposed within the radial passageway 57 is a piston 65 having a plunger element 66 which is adapted to bear against the ball check 61 for urging the same away from its seated position against the valve seat 62. Similarly disposed within the radial passageway 5d is a ball check 67 which is normally biased into engagement with a valve seat 68 formed within the radial passageway 5S by means of a compression spring 69 which is interposed between the plug and a pin 7i?, the latter bearing against the ball check 67. Also disposed within the radial passageway 53 is a piston 71 which is provided with an axially extending plunger 72, the latter being adapted to bear against the ball check 67 for urging the same away from its seated position against the valve seat 68. A uid duct 73 connects the fluid coupling 55 wit the radial passageway 57 and through an auxiliary duct 74 with the fluid supply line 31. At the same time uid will pass through a bypass duct 75 into the radial passageway 5S thereby forcing the piston 71 inwardly within the passageway 5S causing the plunger element 72 tO force the ball check 67 away from the valve seat 68. ln like manner, fluid can be supplied from the tluid coupling S6 to the iiuid channel 32 through a fluid duct 76 into the radial passageway 58 and through an auxiliary duct 77 into the tluid channel 32. A bypass duct 78 also connects the lluid coupling 56 to the radial passageway 57 for biasing the ball check 61 away from the valve seat 62.

Thus, if it is desired to extend the hydraulic cylinder 17 of the Outrigger 15, fluid is pumped into the coupling 5S, through the uid duct 73, forcing the ball check 61 away from the valve seat 62 where the fluid will then pass through the auxiliary duct 74 and into the iluid supply line 31. As the uid chamber 3l) is lled with iluid, the movable hydraulic cylinder 17 will extend in the manner as previously described. At the same time, iiuid will pass through the bypass duct 7S into the radial passageway 53, causing the piston 71 and plunger 72 to bias the ball check 67 away from the valve seat 68. This will, in turn, permit fluid within the iiuid chamber 46 and the iluid channel 32 to pass through the auxiliary duct 77, through the radial passageway 58, out through the fluid duct 76 and the coupling 56. In this connection, it is to be noted that when the Outrigger reaches its fully extended position, iluid under pressure will no longer be supplied to the uid couplings 55, 56, arid both of the ball checks 61, 67, will be seated against the Valve seats 62, 68, respectively, causing the Outrigger 15 to be maintained in a rigid extended position. When it is desired to retract the cylinder 17 in the Outrigger housing 33, uid is supplied to the duid coupling 56 through the fluid duct 76 forcing the ball check away trom the valve seat 63, past the valve seat 68, through the auxiliary duct 77 and into the fluid channel 32. This will cause the hydraulic cylinder 17 to retract to the position as shown in the solid lines of FIG. 4 in the manner as previously described. At the same time that fluid is supplied to the channel 32 and hence chamber 46, uid will pass from the coupling 56 through the bypass duct 78 and into the radial passageway 57, causing the piston 65 and plunger 66 to urge the ball check 61 away from the valve seat 62, against the action of the compression spring 63. This will permit the iluid within the iluid supply line 31 to pass through the auxiliary duct 74, through the radial passageway S7, and out through the uid duct 73 and coupling 55. It is to be noted in this connection that after the cylinder 17 has reached its fully retracted position, there will be no iluid pressure maintained at either of the uid couplings S5, 56, thereby permitting each of the ball checks 61, 67, to be biased into engagement with the valve seats 62, 68, respectively. By means of the above-outlined construction, it can be seen that the Outrigger 15 will always maintain its rigid position after the fluid under pressure is cut o from either of the couplings 5S, 56. Thus, if one of the lluid lines within the hydraulic system, to be hereinafter described, should break, the Outrigger 15 would not collapse, because each of the ball checks 61, 67, is biased against the valve seats 62, 68, respectively, thereby closing each of the chambers 31B, 46, to the fluid source. As the Outrigger 16 is substantially identical to the oute rigger 15 and operates in like manner, it is neither illustrated nor described in detail herein.

Rigidly secured to the upper end of the lengthwise extending supports 9, 19, is a horizontal plate 79 which is formed with a shallow recess Si) for accommodating a derrick mast assembly M which includes an upstanding mast support secured to the plate 79 by means of bolts 32. 'The mast support S1 is hollow and communicates with an aperture 83 formed in the horizontal plate 79 for accommodatiug an auxiliary winch-cable, the latter not being shown, and which may be used with the derricli A. The mast support 81 is formed with an enlarged base portion 84. forming an annular shoulder 85 for supporting a circular worm gear 86 which is rigidly secured to the mast support S1 by means of bolts 87. The enlarged base portion 34 is integrally formed with an outwardly extending annular iiange for supporting an L-shaped bearing 89 which is retained by means of a bearing ring 99 which is secured to the tlange 8S. Bolted to the bearing ring 99 by means of bolts 91 is a mast housing 92 which is rotatable with respect to the mast support 81. The mast housing 92 is integrally formed with an inwardly extending intermediate support plate 93 having an upstanding annular liange 94 which bears against an L-shaped bearing 95, the latter being retained by means of a bearing cap 96 which is secured to the mast support 81 by means of bolts 97. By means of this construction, it is obvious that the l.shaped bearings 89, 95, -act as radial and thrust bearings and support the mast housing 92 in a rotatable position on the mast support S1. The mast housing 92 is provided with a grease tting 9? for supplying grease or other lubricant tO each of the L-shaped bearings 89, 95, and the iiange 83 is annularly groove/.l to accommodate a neoprene rubber annular seal 99 for forming a sealing contact between the bearing ring 99 and the mast support 31.

The intermediate support plate 93 is suitably apertured internally of the mast housing 92 to accommodate a motor support 1111! having an annular flange 191 for supporting a hydraulic motor 1132 including a drive shaft 103 which is conventional, and, therefore, is neither illustrated nor described in detail herein. Rigidly connected to the drive shaft 1413 by means of a suitable coupling 164 is a rotatable shaft 195 having a diametrally reduced lower end 1116 forming an annular shoulder 107, which is supported by suitable ball bearings 16S, the latter being retained by a bearing shoulder plate 199 secured to the housing 92. Secured to the shaft 105 and rotatable therewith is a worm 11i) which meshes with a worm gear 111 which is, in turn, keyed to a stub shaft 112. The stub shaft 112 is journaled in bearings 113 which are mounted within the wall of the mast housing 92 and in bearings 114 which are mounted within an upstanding intermediate wall 115 formed with the mast housing 92.

integrally formed with the stub shaft 112 is a rather small diameter spur gear 116 which meshes with a rather large diameter pinion gear 117, which is, in turn, mounted upon a shaft 11S, the latter being located in downwardly spaced relation to the stub shaft 112 and being journaled in an annular bearing ring 119 secured to the intermediate wall 115. The shaft 118- is journaled at its other end in a set Of tapered roller bearings 129 which are secured between an iruier race 121 and an outer race 122 and which are retained by means of a set of locking nuts 123. integrally formed with the shaft 118 and rotatable therewith is a worm 124 which is adapted to mesh with the worm gear E56. Thus, it can be seen that through the gear reduction system, the hydraulic motor 102 will rotate the rnast housing 92 with respect to the mast support 81. Thus, when the hydraulic motor 162 is actuated by a suitable control system to be hereinafter described, the shaft 1%5 will rotate the worm 116 which will, in turn, rotate the worm gear 111. As the worm gear 111 rotates the stub shaft 112, the spur gear 116 will mesh with the pinion gear 117 and rotate the shaft 118 at a reduced 7 rate. The worm 124 on the shaft 118 which meshes with the Worm gear S6 will cause the housing 92 to rotate with respect to the mast support 81, all as best seen in FIGS. 10-12.

The mast housing 92 is integrally formed with a pair o upstanding ears 125V and extending therebetween is a pin or pintle 126 which is journaled in bearing sleeves 127, the latter being secured to the upstanding ears 125, all as best seen in FG. 13. Pivotally mounted on the pin 126 is a link 12S which consists of a pair of spaced parallel triangular shaped plates 129, 130, each o f which is integrally formed with a pair of converging connecting portions 131, 132, at their lower ends and which, in turn, merge into depending legs 133, 134, respectively. The parallel plates 129, 139, are also formed with upwardly converging connecting portions 135, 135, which integrally merge into upstanding arms 137, 138, respectively. Extending between and connecting each of the vertical triangular plates 129, 13d is a pair of cross-connecting gussets 139, 140, and integrally formed with the upper end of each of the plates 129, 139, is a pair of annular horizontal support anges 141, 142, respectively. Mounted Within each of the upstanding arms 137, 138, are coaxially aligned bearing sleeves 143, 14d, which are, in turn, mounted upon the pin 126 for pivotally securing the link 128 thereto, all as best seen in FIG. 13.

Integrally formed with the mast housing 92 is a pair of rearwardly projecting ears 145, 146. Mounted in and extending between the ears 145, 146, is a pivot pin 147 for rockably supporting a double-acting hydraulic cylinder 148 which terminates in an enlarged mounting boss 149, the latter being suitably apertured for mounting on the pivot pin 147. The pivot pin 147 is integrally provided withY an enlarged head 151i which bears against the ear 1415 and at its other end is provided with a washer 151 and a locking ring 152 for retention within the projecting ears 145, 146. Operatively mounted within the cylinder 148 is a piston rod 153 which terminates in an enlarged mounting boss 154 and is pivotally secured to the lower end of the link 128 by means of a pinV 155 which is mounted in and extends between the depending legs 133, 134. The

pin 155 is Yretained in any conventional manner as is the pin 147 by means of an enlarged head 156 integrally formed on one end and secured to the other endthereof is a washer 157 and locking ring 158.

Extending between each of the vertical triangularly shaped plates 129, 130, intermediate their forward and rearward ends, is a pair of spaced L-'shaped cross-bars 159, 160, and welded to each of the transverse ends thereof are-mounting blocks 161, 162, respectively, which are, in turn, welded to therverticral plates 1,29 and 130. Welded toand extending between each of the cross-bars 159, 169, is a pair of'spaced support brackets 163, 164, for supporting a cable winch V165 which is mounted on a shaft 166, the shaft 166 being, Vin turn, journaled in thesupport brackets 163, 164. Mounted on one extended end of the shaft 166 is a worm gear 167 which'meshes with a worm 158 which is mounted on the drive shaft 169 of a reversible hydraulic motor 171i. The other end of the drive shaft 169 is suitably journaled in the vertical flange of the crossbar 169 and the motor 1791s mounted on the underside of the cross-bar 159. The hydraulic motor 17@ is conventional and, therefore, neither illustrated nor described in detail herein, and'is operated bya suitable control system to be hereinafter described. l Thecable winch 165 is pr ovided with a cable 171 of the type normally used in Winches. By reason of the gear reduction between the worm gear 167 and the Worm 168,V it can be seen that the cable winch165 will not turnv unauthorizedly when a heavy load is connected to the cable 171. Extending between thetriangular plates 129, 139, is a pivot pin 172 which is journaled in a pair of bearing sleeves 173, 174, each of which is mounted in the upstanding arms 137, 138, respectively. The pin 172 is substantially identical to the previously described pin 126 and is retained in the arms 137, 138, in like manner. Pivotally mounted on the pin 172 is a main boom 175 which has a pair of integrally formed rearwardly extending ears 176, 177, each of which is provided with bearing sleeves 178, 179, respectively, and which are mounted on the pin 172 for pivotally supporting the boom 175. The boom 175 is rectangular in cross-section and is formed with a pair of rolled steel U-shaped channels 180, 181, and welded to the upper and lower surfaces thereof is a pair of support plates 182, 183, thereby forming a tubular bore 184. Welded to each of the U-shaped channels 180, 181, and extending laterally outwardly therefrom is a set of U-shaped channel members 18-5, 186, having vertical walls 187, 188, which are spaced from the vertical walls of the channels 18?, 181, respectively, thereby dening a pair of elongated compartments 189, 190.

The boom 175 can be pivoted with respect to the link 128 by means of la double-acting hydraulic cylinder 191 having an integrally formed clevis 192 at one end which is mounted upon the pin 155. Operatively mounted within ,the hydraulic cylinder 191 are a piston 193 and piston rod 194, the latter of which terminates in an enlarged mounting boss 195 for accommodating a pivot pin 196. A U-shaped bracket 197 is welded to the underside of the boom 175 and is provided with ya depending clevis 198 for accommodating the pin 196, the clevis 198 further being reinforced by means of a gusset 199. By means of this construction, it can be seen that when the hydraulic cylinder 191 is actuated by a suitable control system which will be hereinafter described, the boom 175 will pivot with respect to the link 128. The link 128 can, of course, pivot with respect to the mast housing 92 and carry therewith the boom 175. Additionally, the mast housing 92 can rotate and swing the boom 17 5 and link 128 to any position within an arc of 360 with respect to the truck T such as to a position as shown in FIG. 24.

Disposed within the tubular bore 184 of the boom 175 and being adapted forV extensible movement therein is an auxiliary boom or stinger 213i?, which is operable kby a double-acting hydraulic cylinder 2411. The cylinder 201 is integrally provided with an enlarged mounting boss 2512 at its forward end which is, in turn, rockably mounted on a pivot pin 293, the latter of which is journaled in bearing sleeves 294, 285, and which are, in turn, mounted within the vertical walls 187, 188, and the channels 138, 181. The construction of the auxiliary boom or stinger 2116 is similar to the construction of the previously described boom 175 and consists of a pair of spaced opposed U-shaped channel members 206, 207, and welded to the upper and lower ends thereof are connecting plates 2t18, 2139, thereby forming a tubular bore 2113 or rectangular cross-section. Interconnecting the bight portions of each of the channel members 2116, 297, is a transversely extending rectangular support plate 211. The double-acting hydraulic cylinder 261 is disposed within and extends axially through the tubular bore 210 and operatively mounted within the cylinder 2131 is a piston 21'? having an extended piston rod 213. Integrally formed onthe rearward end of the piston rod 213 is an enlarged mounting boss 214 which is pivotally mounted on a pivot pin 215, the pivot pin 215 being, in turn, disposed within bearing collars 216, 217, which are, in turn, mounted within the vertical walls of the Ychannel members 29d, 297. The bearing collars 216, 217, are further reinforced by a pair of vertical support plates 218, 219, which extend between and are welded to the upper and lower walls of the auxiliary boom 211)- Thus, it can be seen that when the piston rod 213 is extended, it will extend the auxiliary boom 200 outwardly of the free end of the main boom 175. Y y

Since a great deal of the weight which will be connected to the cable 171 will be imposed upon the auxiliary boom 2138, the vertical walls of the channel members 285, 2517, are provided with rectangular rub plates 229, 221, each of 'which is provided with relatively flat 

1. A SINGLE BOOM DERRICK UNIT FOR MOBILE PLATFORMS AND THE LIKE, SAID DERRICK UNIT COMPRISING SUPPORT MEANS, A MAST ASSEMBLY ROTATABLY MOUNTED ON SAID SUPPORT MEANS, A BOOM OPERATIVELY MOUNTED ON SAID MAST ASSEMBLY AND BEING ADAPTED TO SWING THROUGH AN ARC IN A VERTICAL PLANE WITH RESPECT TO SAID MAST ASSEMBLY, SAID BOOM HAVING A FIRST SECTION PIVOTALLY CONNECTED AT A FIRST PIVOT POINT TO THE MAST ASSEMBLY AND A SECOND SECTION WHICH IS PIVOTALLY CONNECTED TO THE FIRST SECTION AT A SECOND PIVOT POINT, SAID FIRST PIVOT POINT AND SECOND PIVOT POINT LYING WITHIN THE SAME HORIZONTAL PLANE WHEN SAID FIRST SECTION IS EXTENDED IN A HORIZONTAL POSITION, SAID FIRST SECTION BEING PROVIDED WITH AN OFFSET PORTION THAT PROJECTS OUTWARDLY AND DOWNWARDLY FROM THE SECOND PIVOT POINT WHEN SAID FIRST AND SECOND PIVOT POINTS LIE IN A SUBSTANTIALLY HORIZONTAL PLANE, SAID OFFSET PORTION HAVING A THIRD PIVOT POINT THAT LIES DOWNWARDLY AND OUTWARDLY FROM THE SECOND PIVOT POINT WHEN SAID FIRST AND SECOND PIVOT POINTS LIE IN A SUBSTANTIALLY HORIZONTAL PLANE, FIRST HYDRAULIC RAM MEANS CONNECTED TO THE MAST ASSEMBLY AND TO THE THIRD PIVOT POINT FOR SWINGING SAID FIRST SECTION WITH RESPECT TO SAID MAST ASSEMBLY, SECOND HYDRAULIC RAM MEANS CONNECTED TO THE THIRD PIVOT POINT AND THE SECOND SECTION FOR SWINGING IT WITH RESPECT TO THE FIRST SECTION, AND HYDRAULIC MOTOR MEANS MOUNTED WITHIN AND BEING OPERATIVELY CONNECTED TO SAID MAST ASSEMBLY FOR ROTATING SAID MAST ASSEMBLY WITH RESPECT TO SAID SUPPORT MEANS. 